Rotate object to face up from sphere

I need to rotate an object so that it is always “up” from a sphere like it would be on a planetary surface. I have tried using Quaternion.LookRotation but as you would guess this just makes the object face the ground. Is there an easy way to go about calculating the rotation of the object so it is always up relative to a point on a sphere?

Try adding this logic to your object:

var sphere : Transform;

function Update() {
    var v3 = transform.position - sphere.position;
    transform.rotation = Quaternion.ToFrom(transform.up, v3) * transform.rotation;